function animate_lunbo(obj, target, callback) {
    clearInterval(obj.timer);
    obj.timer = null;
    if (obj.offsetLeft < target) {
        obj.timer = setInterval(function () {
            if (obj.offsetLeft < target) {
                // 缓动算法 目标值见现在的值/10
                var step = (target - obj.offsetLeft) / 10;
                step = Math.ceil(step);
                obj.style.left = obj.offsetLeft + step + 'px';
            } else {
                clearInterval(obj.timer);
                if (callback) {
                    callback();
                }
            }
        }, 15);
    } else {
        obj.timer = setInterval(function () {
            if (obj.offsetLeft > target) {
                // 缓动算法 目标值见现在的值/10
                var step = (target - obj.offsetLeft) / 10;
                step = Math.floor(step);
                // console.log("obj.offsetLeft > target");
                // console.log(obj.offsetLeft + '>' + target);
                obj.style.left = obj.offsetLeft + step + 'px';
            } else {
                clearInterval(obj.timer);
                if (callback) {
                    callback();
                }
            }
        }, 15);

    }
}